title: CRYPTOCHROME is a blue-light sensor that regulates neuronal firing rate.
abstract: Light-responsive neural activity in central brain neurons is generally conveyed through opsin-based signaling from external photoreceptors. Large lateral ventral arousal neurons (lLNvs) in Drosophila melanogaster increase action potential firing within seconds in response to light in the absence of all opsin-based photoreceptors. Light-evoked changes in membrane resting potential occur in about 100 milliseconds. The light response is selective for blue wavelengths corresponding to the spectral sensitivity of CRYPTOCHROME (CRY). cry-null lines are light-unresponsive, but restored CRY expression in the lLNv rescues responsiveness. Furthermore, expression of CRY in neurons that are normally unresponsive to light confers responsiveness. The CRY-mediated light response requires a flavin redox-based mechanism and depends on potassium channel conductance, but is independent of the classical circadian CRY-TIMELESS interaction.
authors.affiliation: Department of Physiology and Biophysics, University of California-Irvine, Irvine, CA 92697, USA.
authors.forename: Keri J
authors.initials: KJ
authors.lastname: Fogle
authors.forename: Kelly G
authors.initials: KG
authors.lastname: Parson
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Dahm
authors.forename: Todd C
authors.initials: TC
authors.lastname: Holmes
mesh_terms: D000200:Action Potentials; D000818:Animals; D057906:Circadian Clocks; D002940:Circadian Rhythm; D054910:Compound Eye, Arthropod / Q000502:physiology; D056931:Cryptochromes / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D005415:Flavins / Q000378:metabolism; D017344:Genes, Insect; D008027:Light; D009154:Mutation; D009474:Neurons / Q000502:physiology; D010084:Oxidation-Reduction; D018408:Patch-Clamp Techniques; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism
chemical_list: D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005415:Flavins; C119828:cry protein, Drosophila; C096445:tim protein, Drosophila